Word: neutrinos
(lookup in dictionary)
(lookup stats)
Dates: during 1990-1999
Sort By: most recent first
(reverse)
DIED. FREDERICK REINES, 80, Nobel-prizewinning scientist known as the father of neutrino physics; in Orange, Calif. Undeterred by skeptics who doubted the invisible neutrino's existence, Reines persevered, often locking himself for hours in his lab, where he could be heard indulging his other great passion: singing opera...
Physicists love nothing more than announcing a discovery that rewrites the textbooks--unless, perhaps, it's a discovery that rewrites two textbooks at once. That's evidently what happened last week at a scientific conference in Japan. An international team of 120 physicists reported that the neutrino, a subatomic particle long thought to be utterly without mass, actually weighs in at a tiny fraction of the mass of the electron (until now, the lightest particle known). For elementary-particle physicists, that means their most basic theories will have to be rewritten; for astronomers, it means that the missing "dark matter...
Evidence that neutrinos have mass has been reported before, but the measurements were so marginal that they left more room for doubt than confidence. Not this time. The Super-Kamiokande neutrino observatory, a stainless-steel chamber filled with 12.5 million gal. of water, lined with sensitive light detectors and located deep underground in an old zinc mine near the city of Takayama, is among the most sensitive instruments of its kind in the world. The physicists who use it are widely recognized as extremely careful experimenters. And, says University of Hawaii physicist John Learned, there wasn't much doubt about...
...particle physicists, the answer hardly matters; the mere fact of neutrino mass will force a rethinking of the "standard model"--the theoretical framework of all subatomic physics. For cosmology, there could be even more tangible consequences. The universe is teeming with neutrinos--so many that trillions of them pass through every human being on Earth every second (fortunately, without doing any damage). Even a minuscule mass could give them enough combined gravity to slow the expansion of the universe that followed the Big Bang. They might conceivably even reverse it, leading to a cosmic catastrophe aptly named the Big Crunch...
...short term, the success of the Japanese experiment could change a few of physics' fundamental laws -- if the results hold up. "The concept of the massive neutrino has been proven -- and then disproven -- before," adds Lemonick. "But these guys are considered the best in the world, and their facility is considered the best in the world. And they're confident. So this is very credible...